1. Field of the Invention
The present invention relates to a switching converter and a semiconductor device.
2. Description of the Related Art
A switching converter is a constant-voltage circuit with which a constant output voltage can be obtained regardless of the value of an input voltage, and the switching converter is used for a power supply circuit together with a rectification circuit or the like. In particular, a power supply circuit including a switching converter is also referred to as switching power source or switching regulator.
The switching type switching converter outputs a voltage of a predetermined level in such a manner that a voltage with a pulse waveform is formed using an input voltage by a switching element and the voltage is smoothed or held in a coil, a capacitor, or the like. With the switching type switching converter, internal power loss can be lower theoretically, whereby the power conversion efficiency can be high and heat radiation due to power loss can be suppressed in comparison with a linear type switching converter utilizing voltage drop due to resistance. Therefore, in a semiconductor device which needs a high output voltage, such as a microprocessor, a power supply circuit including the switching type switching converter is often used.
Furthermore, a switching regulator provided with a main switch, a starter switch for controlling switching of the main switch, a high-pressure portion including a starting resistor that is provided for starting the starter switch, and a control portion for processing a low voltage signal is known (see Patent Document 1).